The Labour-Green proposal to cut Kiwi householders' power prices through radical market reform has been given the thumbs-up by consumer groups, but energy sector commentators are divided on the plan.

The two parties estimate the plan would save as much as $330 a year, close to half the $770 increase in annual power bills sustained by households over the last 15 years.

Labour leader David Shearer said prices had risen due to power companies extracting "super profits" paid for by domestic consumers.

Consumer NZ chief executive Sue Chetwin said the electricity market wasn't working for New Zealanders.

"Prices keep going up for residential consumers and flatline or drop for industrial and commercial users. This proposal may be the circuit breaker."

She congratulated Labour and the Greens for an idea that was "definitely worth having a look at".

Grey Power president Roy Reid welcomed the prospect of $300 off an annual bill. "For our members it would be a tremendous saving."

The chief executive of Meridian Energy-owned online electricity store Powershop, Ari Sargent, said consumers' power bills would fall but the question was how it would be funded. "There's nothing in there that'll fundamentally shift the cost of ... power so it's just a wealth transfer from generator-retailers to consumers."

But energy analysts Molly Melhuish and Bryan Leyland said the new plan would address power companies "gaming" the wholesale market to ensure they maximised profits.